When I’m at a Chinese place and want spicy, I’m honest about it: “Almost painful, please.” Sometimes we’d hear the chefs laughing when they heard/saw our order. No chef has hurt me when I’ve used that phrase.
My BF put ‘mild’ on an online order for me even after saying I wanted my dinner ‘almost painful.’ He’s too protective, and I was V disappointed. Hunan chicken is sposed to be almost painful!